Who has been buying Koatsu Gas Kogyo Co., Ltd. stock?

9 distinct investors have filed 8 disclosed large-shareholding filings in Koatsu Gas Kogyo Co., Ltd. (4097), most recently on 2026-03-18. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.

How many insider filings does Koatsu Gas Kogyo Co., Ltd. have?

Koatsu Gas Kogyo Co., Ltd. has 8 buy-side and 6 sell-side disclosures on record, covering ¥8.7B ($56.1M) in total reported value, spanning 2021-12-21 to 2026-03-18.

Where does StockDrifts get Koatsu Gas Kogyo Co., Ltd. insider data?

From EDINET large-shareholding (5%+) reports — the official filing system run by the Financial Services Agency (Japan). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from EDINET.

Do insider buys in Japanese stocks predict returns?

Not uniformly. StockDrifts scored 101,000+ Japanese large-shareholding filings on fixed 12-month forward returns and found the predictive power concentrated in specific filer types and filing patterns rather than spread evenly across all disclosures.

Koatsu Gas Kogyo Co., Ltd. 4097

Company

高圧ガス工業株式会社Koatsu Gas Kogyo Co., Ltd.

Investors

Buys

Total Value

¥8.7B ($56.1M)

Avg Return

+34.26%

Last Filing

2026-03-18

Koatsu Gas Kogyo Co., Ltd. (4097) has 8 disclosed large-shareholding filings and 6 disclosed disposals on record, filed by 9 distinct investors. Together those filings cover ¥8.7B ($56.1M) in reported transaction value. The earliest filing StockDrifts holds for Koatsu Gas Kogyo Co., Ltd. is dated 2021-12-21; the most recent is 2026-03-18. All of it is parsed from EDINET large-shareholding (5%+) reports, the official disclosure system operated by the Financial Services Agency (Japan). Across these filings the average return since disclosure is +34.26%, measured from each filing date to the latest available close.

Price & insider activity (12 months)

Recent filings

Date	Type	Source	Insider	Purpose	Shares	Price at filing	Return	Value
2026-03-18	SELL	unknown	ブランデス・インベストメント・パートナーズ・エル・ピー(Brandes Investment Partners, L.P.) Brandes Investment Partners, L.P.	other	2.7M	¥1,158	+5.2%	¥792M ($5.1M)
2026-03-11	SELL	unknown	デンカ株式会社 Denka Company Limited	other	5.5M	¥1,125	+2.4%	¥975M ($6.3M)
2025-06-05	BUY	Market Buy	ブランデス・インベストメント・パートナーズ・エル・ピー(Brandes Investment Partners, L.P.) Brandes Investment Partners, L.P.	other	3.4M	¥1,016	+8.1%	¥615M ($4.0M)
2025-03-05	BUY	unknown	ブランデス・インベストメント・パートナーズ・エル・ピー(Brandes Investment Partners, L.P.) Brandes Investment Partners, L.P.	other	2.8M	¥828	+32.6%	¥2.3B ($15.1M)
2024-07-29	BUY	negotiated	三菱UFJアセットマネジメント株式会社 Mitsubishi UFJ Financial Group Inc.	passive	180.6K	¥940	+16.8%	¥78M ($506K)
2024-07-29	BUY	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	2.5M	¥940	+16.8%	¥2.3B ($15.0M)
2024-07-29	SELL	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	919.4K	¥940	-16.8%	¥178M ($1.1M)
2024-07-05	BUY	unknown	髙山眞司 Takayama Sinji	strategic	7.7M	¥978	+12.3%	¥7.6B ($48.7M)
2024-07-05	SELL	unknown	難波太郎 Nanba Taro	other	0	¥978	-12.3%	¥7.1B ($45.9M)
2024-07-05	BUY	unknown	髙山眞司 Takayama Sinji	strategic	7.7M	¥978	+12.3%	¥7.6B ($48.7M)
2023-12-13	BUY	unknown	デンカ株式会社 Denka Company Limited	other	6.9M	¥858	+28.0%	¥5.9B ($38.2M)
2023-12-13	SELL	unknown	デンカ株式会社 Denka Company Limited	other	6.3M	¥858	-28.0%	¥501M ($3.2M)
2022-05-19	BUY	Market Buy	難波太郎 Nanba Taro	strategic	7.3M	¥630	+74.3%	¥354M ($2.3M)
2022-05-19	BUY	unknown	難波太郎 Nanba Taro	strategic	7.3M	¥630	+74.3%	¥354M ($2.3M)
2022-01-26	SELL	unknown	藤井助三郎 Fujii Sukesaburou	other	0	¥749	-46.6%	¥4.9B ($31.8M)
2022-01-26	BUY	unknown	難波太郎 Nanba Taro	strategic	6.7M	¥749	+46.6%	¥5.0B ($32.4M)
2021-12-28	BUY	Market Buy	日本酸素ホールディングス株式会社 NIPPON SANSO HOLDINGS CORPORATION	strategic	3.1M	¥785	+39.9%	¥92M ($591K)
2021-12-21	BUY	Market Buy	難波太郎 TARO NANBA	strategic	7.2M	¥765	+43.5%	¥438M ($2.8M)
2021-12-21	BUY	unknown	難波太郎 TARO NANBA	strategic	7.2M	¥765	+43.5%	¥438M ($2.8M)

Frequently asked questions

Who has been buying Koatsu Gas Kogyo Co., Ltd. stock?: 9 distinct investors have filed 8 disclosed large-shareholding filings in Koatsu Gas Kogyo Co., Ltd. (4097), most recently on 2026-03-18. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.
How many insider filings does Koatsu Gas Kogyo Co., Ltd. have?: Koatsu Gas Kogyo Co., Ltd. has 8 buy-side and 6 sell-side disclosures on record, covering ¥8.7B ($56.1M) in total reported value, spanning 2021-12-21 to 2026-03-18.
Where does StockDrifts get Koatsu Gas Kogyo Co., Ltd. insider data?: From EDINET large-shareholding (5%+) reports — the official filing system run by the Financial Services Agency (Japan). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from EDINET.
Do insider buys in Japanese stocks predict returns?: Not uniformly. StockDrifts scored 101,000+ Japanese large-shareholding filings on fixed 12-month forward returns and found the predictive power concentrated in specific filer types and filing patterns rather than spread evenly across all disclosures.

Source filings

Every trade listed above is disclosed in EDINET large-shareholding (5%+) reports, filed with the Financial Services Agency (Japan). View the original EDINET filings for Koatsu Gas Kogyo Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.